Commitments and Contingencies - Litigation (Details) $ in Thousands				1 Months Ended	3 Months Ended
	Dec. 28, 2016 USD ($)	Dec. 12, 2016 USD ($) claim	Dec. 31, 2006 USD ($)	Mar. 31, 2011 USD ($)	Mar. 31, 2017 USD ($)	Mar. 19, 2012 USD ($)
Commitments and Contingencies, Disclosure
Potential recovery	$ 4,500
Court of Ouargla Foreign Currency Controls
Commitments and Contingencies, Disclosure
Litigation amount as per judgment				$ 25,700
Payment of contract amount in foreign currency			$ 7,500
Payment of contract amount in domestic currency			$ 3,200
Approximate multiplier of the amount at issue for fines and penalties					4
Court of Ouargla Foreign Currency Controls | Maximum
Commitments and Contingencies, Disclosure
Potential judgment in excess of accrual					$ 17,700
NGH2L
Commitments and Contingencies, Disclosure
Escrow Deposit						$ 3,000
NGH2L | Maximum
Commitments and Contingencies, Disclosure
Monetary damages sought based on alleged breach of contract by NGH2L and alleged tortious interference with contractual relations by Parex					$ 750,000
C J Energy And Subsidiaries
Commitments and Contingencies, Disclosure
Number of allowed unsecured claims | claim		2
Maximum claim distribution to be received		$ 4,850
Maximum obligation amount relating to tax matters		$ 11,500
pro-rate share of warrant to acquire common equity percentage		2.00%